Cytogenetical changes and their relation to survival of bone marrow hemopoietic cells during continuous irradiation.

In this paper the frequency of aberrant cells in the bone marrow of continuously irradiated mice with the dose rates 0.05 Gy/day and 0.50 Gy/day was studied. The aberrant cell values were found to be increased non-proportionally with the accumulated doses and their level was influenced mainly by the irradiation period in the dose range 0.5-5 Gy. The most significant reduction in the lymphocyte number and to some extent the granuloid cells number in the bone marrow occurred in the dose rate 0.50 Gy/day. The frequency of aberrant cells in the bone marrow increased at the same time to 15-20%. Possible mechanisms influencing the different response of cells to irradiation are discussed.